The present invention relates generally to timing or rotational devices. More particularly, the present invention is directed to intermittent driving mechanisms that provide for controlled movement and torque output of a driven member.
Timing devices are utilized to cause a particular event to occur at a specific moment in time. Intermittent gear mechanisms, such as Geneva drives, are timing devices that output intermittent rotation motion of a gear member.
Shown in FIG. 1 is an example of a Geneva drive 10 that is known in the art. The Geneva drive 10 includes a driving member 12 that has a pin 14, along with a gear/driven member 16 that has slots 18-26. During operation, the driving member 12 will continuously rotate, for example, in a counter-clockwise manner. The driven member 16 begins to rotate when the portion of the driving member 12 containing the pin 14 rotates to a position where it engages one of the slots 18-26. As the driving member 12 continues to rotate, the pin 14 of the driving member 12 disengages from, for example, a slot 26, and the driven member 16 comes to a stopped position, while the driving member 12 continues to rotate until it has completed a complete revolution, i.e., a 360 degree rotation.
Typically, the driven member 16 is coupled to a load, for example, a four position switch of an antenna system. Each time the pin 14 engages one of the slots 18-26, the switch moves from one position to another. Each switch position corresponds to the coupling of two predetermined transmission line portions. After the pin 14 disengages from one of the slots 18-26, the driven member 16 comes to a stop and a signal is transmitted through the coupled transmission line portions until the pin 14 engages a second one of the slots 18-26 during the next revolution of the driving member 12.
Although a Geneva drive is able to drive its driven member intermittently, Geneva drives suffer from a sharp increase in speed and a sharp decrease in torque output from the driven member due to the interaction between the pin of the driving member and the slots of the driven member. The slot design of Geneva drives has a steep slope. As a result, the motion of the pin is not easily controlled when the pin drops from the top of a slot to the bottom of the slot.
The impact of the pin when it hits the bottom of a slot causes a load coupled to the Geneva drive to suffer from uncontrolled celebration. The load is coupled to the drive via a coupler, and the drive will be subjected to the force associated with the acceleration of the load when the pine 14 enters one of the slots (18-26). However, the uncontrolled acceleration that occurs when a pin enters a slot of a Geneva drive causes excessive wear and tear on the load coupled to drive, drive due to the force exerted on the drive from the uncontrolled acceleration of the load.
Accordingly, it would be desirable to provide an intermittent driving mechanism that provides controlled motion of the driven members. It would also be desirable to provide intermittent driving mechanisms that prevent excessive wear and tear to the intermittent driving mechanisms and any components that are coupled to it. Further, it would be desirable to provide intermittent driving mechanisms that provide constant speed and torque output from their driven members during angular rotation of the driven members.
In one aspect of the present invention, an intermittent driving mechanism is provided that includes a driving member and a driven member. The driven member is rotatably coupled to the driving member and rotates when the pin engages a first arcuate portion of a channel of the driving member.
In another aspect of the present invention, an intermittent driving mechanism is provided wherein the driven member includes an arm and a pin coupled to the arm.
In another aspect of the present invention, an intermittent driving mechanism is provided wherein the driving member includes a rotating member and a port.
In another aspect of the present invention, an intermittent driving mechanism is provided that includes a driving shaft that is positioned within the port.
In another aspect of the present invention, an intermittent driving mechanism is provided that includes a motor coupled to the driving shaft.
In another aspect of the present invention, an intermittent driving mechanism is provided wherein the pin is one of four pins.
In another aspect of the present invention, an intermittent driving mechanism is provided wherein the arm is one of four arms.
In another aspect of the present invention, an intermittent driving mechanism is provided wherein the driven member rotates one-fourth of a revolution for every revolution of the driving member.
In another aspect of the present invention, an intermittent driving mechanism is provided wherein the driven member comes to a stop position when the pin exits the second arcuate portion.
In another aspect of the present invention, an intermittent driving mechanism is provided wherein a slot is positioned between the first arcuate portion and the second arcuate portion.
In another aspect of the present invention, an intermittent driving mechanism is provided wherein the plate is circular.
In yet another aspect of the present invention, a method for operating an intermittent driving mechanism is provided that includes rotating a driving member, and moving a pin of a driven member in an arcuate channel of the driving member to cause the driven member to rotate.
In another aspect of the present invention, a method for operating an intermittent driving mechanism is provided wherein the channel includes a first arcuate portion and a second arcuate portion and the slot is positioned intermediate the first and second arcuate portions.
In another aspect of the present invention, a method for operating an intermittent driving mechanism is provided that includes rotating the driving member one complete revolution and rotating the driven member one-quarter of a revolution.
Further in another aspect of the present invention, an intermittent driving system is provided that includes a means for rotating a driving member and a means for moving a pin of a driven member into an arcuate channel of the driving member.
Moreover, in another aspect of the present invention, an intermittent driving mechanism is provided that includes a driving member having a slot formed in a channel, and a driven member rotatably coupled to the driving member. The driven member has a pin that engages the slot of the driving member after the driving member causes the pin to enter the channel.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.